package com.ddyx.common.utils.encrypt;

import lombok.extern.slf4j.Slf4j;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * 获取文件md5值
 * @author XYZH
 *
 */
@Slf4j
public class MD5FileUtil {

    protected static char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6',  
            '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };  
    protected static MessageDigest messagedigest = null;  
    static {  
        try {  
            messagedigest = MessageDigest.getInstance("MD5");  
        } catch (NoSuchAlgorithmException e) {
            log.error("MD5FileUtil messagedigest初始化失败", e);
        }  
    }  
  
    public static String getFileMD5String(File file) throws IOException {
    	FileInputStream in =null;
    	try {
    		in = new FileInputStream(file);
            FileChannel ch = in.getChannel();  
            MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY, 0,  
                    file.length());  
            messagedigest.update(byteBuffer);
            return bufferToHex(messagedigest.digest());  
    	}finally {
    		if(in!=null)
    			in.close();
    	}
    }  
    
    public static String getFileMD5String(InputStream in) throws Exception{  
        if(in != null){
        	byte buffer[] = new byte[1024];  
            int len;
            try{
           	 while ((len = in.read(buffer, 0, 1024)) > 0) {  
           		 messagedigest.update(buffer, 0, len);  
                } 
               return bufferToHex(messagedigest.digest());
            }catch (Exception e){
            	e.printStackTrace();
            }finally{
            	in.close();
            }
        }
		return "";
    }
  
    public static String getFileMD5String(byte[] byteArray) throws Exception{  
        try{
        	messagedigest.update(byteArray);  
        	return bufferToHex(messagedigest.digest());
        }catch (Exception e){
        	e.printStackTrace();
        }
		return "";
    }
    
    public static String getMD5String(String s) {  
        return getMD5String(s.getBytes());  
    }  
  
    public static String getMD5String(byte[] bytes) {  
        messagedigest.update(bytes);  
        return bufferToHex(messagedigest.digest());  
    }  
  
    private static String bufferToHex(byte bytes[]) {  
        return bufferToHex(bytes, 0, bytes.length);  
    }  
  
    private static String bufferToHex(byte bytes[], int m, int n) {  
        StringBuffer stringbuffer = new StringBuffer(2 * n);  
        int k = m + n;  
        for (int l = m; l < k; l++) {  
            appendHexPair(bytes[l], stringbuffer);  
        }  
        return stringbuffer.toString();  
    }  
  
    private static void appendHexPair(byte bt, StringBuffer stringbuffer) {  
        char c0 = hexDigits[(bt & 0xf0) >> 4];  
        char c1 = hexDigits[bt & 0xf];  
        stringbuffer.append(c0);  
        stringbuffer.append(c1);  
    }  
  
    public static boolean checkPassword(String password, String md5PwdStr) {  
        String s = getMD5String(password);  
        return s.equals(md5PwdStr);  
    }  
    
    public final static String MD5(String s) {
		char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
		try {
			byte[] btInput = s.getBytes();
			// 获得MD5摘要算法的 MessageDigest 对象
			MessageDigest mdInst = MessageDigest.getInstance("MD5");
			// 使用指定的字节更新摘要
			mdInst.update(btInput);
			// 获得密文
			byte[] md = mdInst.digest();
			// 把密文转换成十六进制的字符串形式
			int j = md.length;
			char str[] = new char[j * 2];
			int k = 0;
			for (int i = 0; i < j; i++) {
				byte byte0 = md[i];
				str[k++] = hexDigits[byte0 >>> 4 & 0xf];
				str[k++] = hexDigits[byte0 & 0xf];
			}
			return new String(str);
		}
		catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}
  
//    public static void main(String[] args) throws Exception {  
//        long begin = System.currentTimeMillis();  
//  
//        /*File big = new File("D:\\code\\ci\\resources\\src\\main\\webapp\\styles\\images\\bg_01.png");  */
//        File big = new File("D:\\bg.png");  
//        String md5 = getFileMD5String(big);  
//        String md51 = getFileMD5String(new FileInputStream(big));
//        long end = System.currentTimeMillis();  
//        System.out.println("md5:" + md5);  
//        System.out.println("md51:" + md51);  
//        System.out.println("time:" + ((end - begin) / 1000) + "s");  
//  
//    }
    
    public static void main(String[] args) {
		String md5 = MD5FileUtil.MD5("dingdangyixia");
		System.out.println(md5);
	}
}
